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  1. Naked Science Forum
  2. Profile of alancalverd
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Messages - alancalverd

Pages: [1] 2 3 ... 57
1
Just Chat! / Re: Why was society more vapid and conformist during the 2010-2015 time period?
« on: 25/01/2023 16:14:39 »
Interesting to note that the Big Brother franchise is owned by Bazalgette. Why does the name seem familiar? Sir Joseph Bazalgette was the Victorian engineer charged with the task of rebuilding London's sewage system, taking sh1t out of people's houses . Same family (great grandson), same business, just reversing the flow and piping it into their living rooms.   
The following users thanked this post: paul cotter

2
Physics, Astronomy & Cosmology / Re: Twin paradox confusion
« on: 21/01/2023 11:07:56 »
Quote from: Dimensional on 20/01/2023 23:54:32
I am pretty sure they can synchronize clocks as one twin passes by the other.

Not possible!

The colloquial use of "gentlemen, synchronise your watches, it will be 0100 in 5,4,3,2,1,now" assumes that once zeroed, all the watches will run at the same rate, so if we aim to arrive over the target at 0500 we will crash into one another.

The statement Δt' = Δt/√ (1 - vē/cē)  clearly shows  that if the watches are identical,  Δt' = Δt only if v = 0, that is that identical watches will not run at the same rate from each other's viewpoint if they are moving with respect to one another.

Not a problem when we are all flying from Scampton to Edersee because our accelerations will be pretty much the same, but there have been enough experiments that demonstrate the effect of one aircraft accelerating and the other staying on the ground.
The following users thanked this post: hamdani yusuf

3
Just Chat! / Re: Is there a universal moral standard?
« on: 17/01/2023 17:46:32 »
What influence have the children of Karl Marx, Pope John Paul II, Adolf Hitler, Jesus Christ.... had on society? And did these rather significant characters themselves inherit power and influence?
The following users thanked this post: Zer0

4
Just Chat! / Re: Is there a universal moral standard?
« on: 12/01/2023 18:44:26 »
Quote from: hamdani yusuf on 12/01/2023 11:45:46
Their consciousness can be a bit higher than children, but clearly lower than average adults.
Measuring something you can't define is a step on the road to insanity. Or a symptom of terminal philosophy, for which there is no cure.
The following users thanked this post: Zer0

5
Physics, Astronomy & Cosmology / Re: What is the exact cause of the time dilation of the twin?
« on: 12/01/2023 18:39:05 »
Thrown - acceleration. Change of velocity vector from one ship to another - acceleration. Acceleration is nothing more or less than a change of velocity: speed, direction or both.

If both clocks have the same velocity, there is no discrepancy between them (observed fact!).
The following users thanked this post: Zer0

6
Physics, Astronomy & Cosmology / Re: What is the exact cause of the time dilation of the twin?
« on: 12/01/2023 08:48:18 »
Quote from: Dimensional on 12/01/2023 00:07:52
Yes, I meant to say that the video from Fermilab says that no acceleration is needed. 
Then it's wrong! If there is no acceleration between the twins, there is no relative speed, therefore no time discrepancy. If they were always moving relative to one another, they aren't twins because there never was any synchronicity.
The following users thanked this post: Zer0

7
Just Chat! / Re: Is there a universal moral standard?
« on: 11/01/2023 22:40:14 »
Of course they would fight. Catholics v Protestants, Sunni v Cher, Hasidic v Reform, you name it. The function of religion is to make people despise one another.

At least football hoolgians fight about something real that affects their lives.

Wars are fought for the glory of politicians and the profits of their family companies. The outcome doesn't matter, as long as there is money to be made supplying the weapons and repairing the damage. The combatants are lucky if they get to go home.
The following users thanked this post: Zer0

8
Technology / Re: How were images transferred before the digital age?
« on: 08/01/2023 18:31:53 »
Quote from: Petrochemicals on 07/01/2023 23:33:19
Ahh video, hours and hours of people recording their holidays on camcorders,
Before Facebook, you had to photograph your lunch, rush to the chemist, get the film developed, make 25 postcard prints,then go to the post office and send them to your friends, by which time the meal was cold.
But whilst Evan can't see his recent photos on  his new computer, I still have black and white prints of equipment I built nearly 60 years ago, and if you want a good picture of an extinct bison there are plenty of 40,000 year old cave paintings that show you how to hunt them with spears.
The following users thanked this post: evan_au

9
New Theories / Re: If there was one Big Bang event, why not multiple big bangs?
« on: 04/01/2023 22:58:25 »
Quote from: Bogie_smiles on 27/12/2022 02:19:47
When the survival of the fittest is achieved, the conditions for the on-going evolution of higher intelligence are in place
The fittest seem to be viruses, capable of extremely rapid evolution and population growth compared with their hosts. Not sure how you define intelligence, but I think the average virus has an immeasurably low IQ.
The following users thanked this post: Bogie_smiles

10
Physics, Astronomy & Cosmology / Re: Why do my Christmas lights give such a nice ambience?
« on: 04/01/2023 16:28:42 »
Cataract rarely mists the entire lens at once - it tends to form in small nuclei which spread out with time. If all the n nuclei have radius r and the lens aperture is R, then the proportion of light not passing through the cataract is
(R2-nr2)/R2
 which clearly increases rapidly with R for any fixed value of r. I first made this diagnosis when a friend remarked that she couldn't read the signs in a brightly-lit supermarket but had no problem driving at night, and an optician confirmed it a few days layer.

Image "sharpness" increases with decreasing aperture either because the lens is distorted or because you define sharpness as depth of focus. An animal eye, unlike a camera, doesn't really rely on d.o.f. but tends to focus sharply on the object of interest*, so only the first condition applies: the infinitesimal segment of any convex surface approximates to spherical!


*serious problem for sailors and aviators! Thanks to lots of evolution the relaxed "normal" human eye doesn't focus at infinity but at around 20m - where you might find a natural predator or prey that you can do something about. Not a lot of use if you are trying to spot a hostile or converging aircraft in the "blue bowl".

   

 
The following users thanked this post: paul cotter

11
Physiology & Medicine / Re: Quantum Manifestation Code Review
« on: 30/12/2022 14:23:04 »
And the quantum bit?
The following users thanked this post: paul cotter

12
Physics, Astronomy & Cosmology / Re: why do a lot of people confuse between interference and diffraction?
« on: 30/12/2022 00:21:48 »
I spent several happy years making and interpreting x-ray diffraction photographs, every one of which literally had a hole in the middle to let the primary beam out. If we didn't do that, the scattered radiation from the majority of the x-rays that passed straight through the sample would fog the film and make the diffraction spots difficult to find. Hence an abiding interest in knowing the difference.
The following users thanked this post: hamdani yusuf

13
Physics, Astronomy & Cosmology / Re: why do a lot of people confuse between interference and diffraction?
« on: 27/12/2022 09:51:59 »
Quote from: Eternal Student on 27/12/2022 07:18:58
At some point in the thread you might have told us why you feel the terms need to be kept so separate but I can't find that on scanning through the thread.  Perhaps you could tell us again.

Diffraction occurs at an edge or a point and results in a downstream wavefront with the same wavelength as the original source, appearing to originate from that edge/point.

Interference is the result of superposition of two or more wavefronts producing maxima and minima with a spatial distribution related to the distribution of the sources. 

If you stand in the shadow of a mountain you may hear the radio signal of a station that is just out of your line of sight. The signal strength you receive decreases smoothly as you move away from the station or further "behind" the mountain. Diffraction. This can cause serious radio navigation errors.

If you have two stations transmitting  the same signal, the intensity you receive will vary sinusoidally as you move in any direction  relative to them. Interference. This was used for very precise long range radio navigation systems such as "Knickebeine" and "LORAN".
The following users thanked this post: Eternal Student

14
Physics, Astronomy & Cosmology / Re: Is there an experiment that shows the oscillation in the E field of light?
« on: 21/12/2022 10:38:04 »
There is an underlying misunderstanding here.

The wavelength of visible light is orders of magnitude larger than an atom or molecule. When you walk on sand your speed depends on its bulk properties (wet, dry, compacted...) not the interaction of your foot with each individual grain, though the inter-grain mechanics (sharp, soft....) actually determine the bulk property. 

The fact that for instance μiron is sometimes enormously greater than most other materials is clearly a function of group (domain) behavior rather than that of a single atom.

As the wavelength of EMR approaches atomic dimensions so we need to model the interaction by quantum rather than wave mechanics, as I stated several posts ago.   At the other end of the scale we can measure μ and ε statically for any substance, and as we can see with the dispersion of white light in glass, these parameters vary with wavelength and with the nature of the transmitting medium, since bulk properties ultimately depend on atomic properties. 

So to address HY's problem: Maxwell's equations describe wave propagation. The wave model works well when considering propagation at wavelengths greater than an atom or molecule diameter and also describes diffraction from a crystal lattice (a bulk property), but does not describe the interaction of EMR with individual atoms, for which we have a particle model. 

Maxwell's equations don't "break down" any more than a train timetable "breaks down" when you want to catch a bus - they predict only and exactly what they say they predict.
The following users thanked this post: paul cotter

15
New Theories / Re: An essay in futility, too long to read :)
« on: 17/12/2022 09:45:11 »
Quote from: yor_on on 16/12/2022 13:47:30
As for if funding ones enemies neighbor with weapons and cash is about defending?
I have no enemies, but I'm always ready to support an innocent potential victim against a stated threat from his enemies.
The following users thanked this post: paul cotter

16
New Theories / Re: An essay in futility, too long to read :)
« on: 15/12/2022 16:39:13 »
Quote from: Zer0 on 15/12/2022 14:56:45
How come Canada, Australia & Japan are Not already part of NATO?
Canada was a founding member and is still a member.The others do not have any geographical connection with the North Atlantic.
But don't let the facts spoil a good argument.
The following users thanked this post: Zer0

17
General Science / Re: Is science a religion.........well if not why is it defended as though it were
« on: 15/12/2022 09:15:18 »
It isn't.

AFAIK nobody has ever started a war or tortured anyone to death in defence of  F = Ma.

A few guys were excommunicated or even burned at the stake for suggesting such heresy, but that is the fault of religion, not science.
The following users thanked this post: Zer0

18
General Science / Advent calendar maths question!
« on: 14/12/2022 23:21:07 »
This might amuse those of a mathematical persuasion.

We have a novelty advent calendar. For anyone brought up in a different faith, it counts down the days from 1 to 25 December. Ours consists of two numbered wooden cubes which you can rearrange to display every integer from 25  to zero.

What numbers are painted on each cube? 
The following users thanked this post: Eternal Student

19
New Theories / Re: An essay in futility, too long to read :)
« on: 12/12/2022 18:28:21 »
Quote from: yor_on on 12/12/2022 14:32:18
A spoonful?
That would be quite enough, if the output is continuous, to justify the entire program.
The following users thanked this post: Zer0

20
Just Chat! / Re: was the Manahan project a faliure
« on: 11/12/2022 23:38:02 »
Once the western front was established in Normandy, the overland invasion of Germany was an inevitable progression into territory that had been pretty much bombed and strafed into impotence. It still took a year to complete.

Japan was a very different proposition: it was a long way from the major ground forces building in India and the USA and at the range limit of most bombers, never mind land-based fighters. Its infrastructure had hardly been damaged by a few very costly bombing raids. It still had a functioning defensive navy, and the capability of building enough fighters to reprise the Battle of Britain in the air.

The  planned invasion of Japan involved an estimated 300 - 500,000 fatalities and maybe 10 times as many permanently disabled casualties over 2 -4 years, at a far greater cash cost to the Allied economies.

In terms of bang per buck, no ship, conventional bomber or tank comes within three orders of magnitude to a nuke, never mind the "disposable asset" infantry and unavailable air support you need to actually occupy the territory.

Manhattan was worth every penny to my dad training ground forces in the Far East and The Boss's dad dropping iron bombs on a very resilient enemy dug into the Pacific islands.
The following users thanked this post: Zer0

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